Dispensing pump



April 23, 1929.

W. C. ARMISTEAD DISPENSING PUMP Filed May 21, 1925 2 Sheets-Sheet INVENTOR. y). :Qrm-is 20.1

A TTORNE Y.

INVENTOR.

ATTORNEY.

' W. C. ARMISTEAD April 23, 1929.

DISPENSING PUMP 1925 2 Sheets-Sheet Filed May 21 W 0 ahml'alzacl Patented Apr. 23, 1929.

UNITED STATES I 1,709,966 PATENT orrlcs.

WILLIAM C. ARMISTEA D, OF FORT WAYNE, INDIANA, ASSIGNOR TO S. F. BOWSER & COMPANY, OF FORT WAYNE, INDIANA, A CORPORATION.

DISPENSING PUMP.

Application filed May 21, 1925.

The invention relates to dispensing pumps and it is especially directed to means by which the operation of the pump is controlled.

In the dispensing ofvarious liquids it fre-v quently occurs 'that the quantity of liquid delivered by the pump overflows from the receptacle receiving it and is wasted. This is especially true at filling stations where the customer orders a definite quantity, say five gallons of gasolinefor his automobile tank. The pump mechanism is set and operated to deliver five gallons but the tank is filled before the full amount is delivered and overflows onto the ground. Before the discharge valve can be closed and the pump stopped, the liquid continues to flow through the hose and is lost.

The object of my invention is to provide a dispensing pump with means by which it will be automatically stopped when the liquid reaches a selected level in the receptacle and thereby prevent. all overflowing of the re-.

ceptacle.

The invention consists in means for l0cking the pump mechanism, the means being operated by a movable member that is responsive to an unbalanced pressure upon its opposite sides caused when the liquid reaches a predetermined level in the receptacle.

An adaptation of the invention is illustrated in the accompanying drawings in which Figure 1 is an elevational view of a simple form of dispensing pump provided with the invention, Fig. 2 an'enlarged detail view of the lock operating mechanism, and Fig. 3 a side view of the nozzle and air line.

In the illustrative embodiment of the invention the pump is any form commonly in use for dispensing liquids. A plunger 1 within the cylinder 1 draws the liquid from a reservoir, usually buried in the ground, and delivers it through a filter 2 and the pipe 3 to the discharge hose 4, a valve 5 controlling the discharge of the liquid through the hose.

A rack bar 6 is suitably attached to the plunger rod 1 and the bar is raised and lowered by a gear or train of gears within the case 7 and having a connection to the hand crank 8.

A latch 9 is pivoted at 10 to a lug or bracket 11 on the case 7 or pump frame 12 and is adapted to swing into engagement with the teeth of the rack and hold the rack and the pump plunger from further movement.

Serial 110,131,774.

which is suitably attached to the hose 4 and may be disposed inside or on the exterior of the hose. The lower end of the conduit 17 terminates at a predetermined distance above the discharge end of the hose or of the nozzle 18 thereon, so that when the nozzle is inserted into a receptacle, such as the gasoline tank of an automobile, the said lower end of the conduit will determine the approximate height of the liquid the tank should contain and not overflow.

The lower end of the pipe line 16 is connected to a cylinder 19 mounted on the pump frame. A plunger 20 within the cylinder 19 is secured to a plunger rod 21 the upper end of which is suitably secured to the rack mechanism 6, so that as the rack bar is reciprocated the plunger 20 will also be reciprocated in the cylinder 19. As the plunger 20 risesavacuum isiormed in the cylinder 19 and external air enters the cylinder through the conduit and'the pipe line, the discharge of the i air being through said line and conduit. As

long as air is moving through the conduit and pipe line the member 13 is inoperative and the latch remains in its normal depending position, but when the open end of the conduit is closed, the air pump upon its succeeding up-st'roke creates a partial vacuum in the conduit and the pipe line that is almost instantly effective to unbalance the pressure upon the member 13, causing the member 13 to collapse or exert a pull on the latch and cause the latch to swing toward the rack and pass into the space between two of the teeth on the same. The latch and the teeth on the rack are so shaped that when the latch abuts a tooth on the rack the tooth as it moves up or down will draw the latch into the space between that tooth and the next one on the rack and thereby lock therack against further movement.

When the hose nozzle is inserted into the tank to be supplied and the pump is operated to deliver the quantity of liquid requested the liquid will discharge into the tank in the usual 'manner. Atmospheric air will be drawn through the conduit and the pipe line by the air pump. Should the level of the liquid reach the lower end of the conduit 17 and close it, a partial vacuum is formed in the pipe line unbalancing the member 13 and causing it to throw in the latch.

In Fig. 3 I form a seat 22 in the outer end of the vacuum and cause the operation of the latch mechanism. It also prevents the liquid from passing intp the air line.

It is evident that any form of latch may be used and that it may be designed or arranged to engage any part of the plunger mechanism of the pump.

What I claim is: 1. In a dispensing pump, a pump mecha nism including a plunger and means to actuate the plunger, means to lock the actuating means, a discharge member for the mechamsm, a pneumatic member connected to the lock, a conduit leading from one side of the pneumatic member to a selected pointadjacent thedischarge end of the discharge member for admitting atmospheric air to said side of the pneumatic member, and means operatively connected to the plunger actuating means and having a connection to the conduit for forming a partial vacuum in said conduit and in the pneumatic member when an accumulation of liquid discharged from the discharge member closes the open end of the conduit to unbalance the pressure on the pneumatic member and cause it to move the lock into engagement with the plunger actuating means.

2. In a dispensing pump, a pump cylinder, a plunger AVltlllIl the cylinder, means connected to the plunger for actuating it, a lock adapted to engage the actuating means, a discharge member having communication with the cylinder, a pneumatic member having an operating connection to the lock to cause the lock to engage the actuating means, a conduit having communication with one side of the pneumatic member and terminating at one end at a selected point adjacent to the discharge end of the discharge member for admitting atmospheric air to said pneumatic member, and means operatively connected to the plunger actuating means and having a connection to the conduit to form a partial vacuum in the conduit for unbalancing the pressure on the pneumatic member, said means being responsive to the level of an accumulation of the liquid discharged from the discharge member.

3. The combination with a cylinder and a plunger therein. of a mechanism for actuating the plunger, a lock adapted to be engaged with the mechanism, a discharge member having communication with the cylinder, a pneumatic member connected to the lock for engaging it with the actuating mechanism,

a second cylinder having a plunger therein operatively connected to the said actuating mechanism, means having communication with one side of the pneumatic member and with the second cylinder for admitting atmospheric air to the pneumatic member for balancing the atmospheric pressure thereon, the air-intake of said latter means being at a selected point-adjacent to the discharge end of the discharge member and being adapted to be closed by an accumulation of liquid discharged from the dis harge member Whereupon a partial vacuum is formed in the penumatic member by the second plunger to cause the said member to engage the lock on the actuating mechanism.

4. In a dispensing pump and operating means, including a plunger rack, discharging means, a member to lock the rack, and pneumatic means to operate the locking means and including a pneumatic member operatively connected to'the locking means, an air line having its intake adjacent to the discharge orifice of the discharge means, and having communication with the pneumatic member and means to draw air through said air line, the closing of the intake end of the air line by an accumulation of liquid discharged from said orifice unbalancing the pressure on the pneumatic member and cansing it to operate the locking means.

In witness whereof. I have hereunto set my hand this 9th day of May, 1925.

WILLIAM G. 'ARMISTEAD. 

